LAST EDITED ON Dec-23-18 AT 11:29PM (MST)[p]The 1-10 twist in my .300 shoots excellent with 165s up to 200gr. all day, every day.
The 1-10 shouldn't be a problem for the long ones in the .30 Cal's.
The 1-9 shouldn't be a problem in the 28 Nosler, with up to 175gr. bullets.
Bullet seating depth is the key for accuracy in the heavy for caliber bullets, coupled with a good slow burn rate powder.
I get 3/8" groups out of my 1-10 barrelled .300 win mag with 178gr. ELD-X and 200gr. Accubond at the hundred.
But the seating depth needed to be very long on those 200s.